Os05g0486100
Please input one-sentence summary here.
Contents
Annotated Information
Function
This gene encodes a Ca2+-independent Ser/Thr kinase which is induced by auxin and abscisic acid (ABA). The novel leucine-rich-repeat receptor-like kinase affects the root system architecture by negatively regulating polar auxin transport in rice.[1] Knockdown of OsRPK1 promoted the growth of transgenic rice plants, and increased plant height and tiller numbers. In contrast, over-expressing plants showed undeveloped adventitious roots, lateral roots, and a reduced root apicalmeristem. OsRPK1 over-expression also inhibited the expression ofmost auxin efflux carrier OsPIN genes, which was accompanied by changes in PAT and endogenous free IAA distribution in the leaves and roots. This study demonstrated a common regulatory pathway of root system development in higher plants, which might be initiated by external stimuli via upstream receptor-like kinases and downstream carriers for polar auxin transport.
Wild Type VS. Mutant
Three under-expressing lines:A5, A7, A9
Three over-expressing lines: O1, O7, O8
One week after germination, the growth of the primary embryonic root was delayed in the over-expressing lines, whereas the under-expressing lines had more adventitious root production compared with WT. At the seedling stage, over-expressing lines exhibited significant shorter shoot height and less fresh weight compared with the WT or under-expressing lines. From the seedling to the tillering stage, under-expressing lines had an increased tiller number compared with the WT and over-expressing lines. At the ripening stage, there were significant differences between WT and the transgenic lines in the total and effective tiller number per plant. ComparedwithWT, over-expressing lines showed a 25% decrease in the effective tiller number, leading to a 27% reduction in grain yield per plant(Fig.1)
Over-expressing lines had a smaller root system and fewer adventitious roots . Lateral root formation was severely defective in over-expressing lines. (Fig.2)
Under-expressing lines had well-developed meristems and elongation zones compared with WT, which were slightly defective in over-expressing plants.(Fig.3)
Expression
This gene is predominantly expressed in root tips, leaf blades, and undifferentiated suspension cells, and is markedly induced by treatment with auxin or ABA.
The expression of OsRPK1 in different tissues was analyzed by realtime quantitative PCR. The results showed that OsRPK1 had a higher expression in root tips and leaf blades.Compared with the roots, the expression of OsRPK1 was reduced 5-fold in the stem and 2-fold in the leaf sheath. Real-time PCR analyses showed that the expression of OsRPK1 was induced mainly by exogenous auxin (2,4-D and IAA) and ABA within 12 h of treatment.[1](Fig.4)
Evolution
Data revealed that OsRPK1, which was designated Osi000900.2 and belongs to the LRR-VIII subfamily of RLK/Pelle in rice, had no close homologues in any other plant genome . For example, OsRPK1 shows 68 and 58% identity with EES19713 from Sorghum bicolor and CCB55930 proteins from Vitis vinifera, respectively, and 56% identity with XP_003547844 from Glycine max. In the rice genome, Os03g0329700 and Os01g0816600 proteins share 58 and 56% identity with OsRPK1, respectively. In addition, the results demonstrated that OsRPK1 is a novel leucine-rich-repeat receptor-like kinase (LRRRLK), and no function had been assigned. OsRPK1 contains six periplasmic LRR motifs, one transmembrane domain, and one conserved cytoplasmic kinase domain . The kinase domain contained all 12 conserved sub-domains of the eukaryotic protein kinase, HRDIKSTN in the VIb sub-domain, and GTLGYLDPEY in the VIII sub-domain, indicating that OsRPK1 is a serine/threonine kinase
Receptor-like kinases (RLKs) are a family of transmembrane proteins with versatile N-terminal extracellular domains and C-terminal intracellular kinases.Analysis of four fungal, six metazoan, and two Plasmodium sp. genomes indicates that the family was represented in all but fungal genomes, indicating an ancient origin for the family with a more recent expansion only in the plant lineages.
None of the four fungal genomes examined contained recognizable RLK/Pelle family members. However, the presence of family members in Plasmodium sp. and animal genomes suggests an origin for the RLK/Pelle family in a common ancestor of all genomes examined. The consistently low gene numbers in genomes other than Arabidopsis suggest that a dramatic expansion occurred in the plant lineage. On the other hand, the absence of family members in the fungal genomes examined indicates the RLK/Pelle family may be lost in fungal lineages after fungus-metazoan split.[2] [3]
Labs working on this gene
1.Dept. of Biochemistry & Molecular Biology, College of Life Science, Nanjing Agricultural University, Nanjing 210095, China
2.Japan Biological Information Research Center
3.EMBL Outstation–European Bioinformatics Institute, United Kingdom
4.Department of Biology, McGill University, Canada
5.Department of Genetics, The University of Georgia, USA
6.Center for Information Biology and DNA Data Bank of Japan
7.Graduate School of Information Science and Technology, Hokkaido University, Japan.
References
1.Yu Zou, Xiaoyu Liu, QingWang, Yu Chen, Cheng Liu, Yang Qiu,Wei Zhang, OsRPK1, a novel leucine-rich repeat receptor-like kinase, negatively regulates polar auxin transport and root development in rice, Biochimica et Biophysica Acta 1840 (2014) 1676–1685
2.Shin-Han Shiu and Anthony B. Bleecker, Expansion of the Receptor-Like Kinase/Pelle Gene Family and Receptor-Like Proteins in Arabidopsis, Plant Physiol. 132 (2003) 530–543.
3.S.H. Shiu, A.B. Bleecker, Plant receptor-like kinase gene family: diversity, function, and signaling, Sci. STKE 2001 (2001) RE22.
4.Cui-Cui Shi1, Cui-Cui Feng1, Mei-Mei Yang, Overexpression of the receptor-like protein kinase genes AtRPK1 andOsRPK1 reduces the salt tolerance of Arabidopsis thaliana, Plant Science 217– 218 (2014) 63– 70
5.Takeshi Itoh, Tsuyoshi Tanaka, Roberto A. Barrero, Curated genome annotation of Oryza sativa ssp.japonica and comparative genome analysis with Arabidopsis thaliana, Genome Research 17:175–183 2007
6.Tsuyoshi Tanaka1, Baltazar A. Antonio1, Shoshi Kikuchi, The Rice Annotation Project Database (RAP-DB): 2008 update, Nucleic Acids Research, D1028–D1033 ( 2008)
